Top 5 things that will get you bored

There are several things that get you bored and unsatisfied with your job if you constantly repeat them and if these things make more than 85% of your everyday work for a longer period of time.

1. Business escalations - if you constantly fight with unsatisfied customers, failing projects, interpersonal problems, etc. If all of these problems end up at your desk too often, you'll get bored.
2. Repetition - you're constantly repeating previously acquired knowledge and really not learning anything new in the professional sense.  
3. "Disconnected" boss - this may seem awkward, but if your boss lets you do too much on your own, you'll get bored eventually. Monitoring also means that someone cares for what you do.
4. Constant pay - you're getting payed same amount of money for your work every month and no change in any direction will also get you bored.
5. Compensating incompetence - if you often compensate incompetence of some of your colleagues and they're not getting sanctioned will eventually get you bored; regardless of whether you're getting rewarded for it.

Most of these points seem like a regular tasks for some jobs, but if there's too much of these you'll definitely get bored at work.

Human mail dispatchers

I've recently read the book Rework by 37signals.com founders.
First of all, I highly recommend that you read it. It'll definitely make you rethink the way you do your business, at least it did to me, and hopefully you'll really rework to some extent.
Basically, book presents an agile approach to starting, running and growing your business. The ideas presented look revolutionary from the point of view described in widely adopted business related books.
One the chapters deals with delegators It's named "Delegators are dead-weight". Delegators are managers that dispatch work to other people, all work. What I've seen in my career is that the delegators are glorified as great managers and delegating is sometimes pointed out as the single-best management virtue. Don't do it yourself, delegate, I was often said. Delegation is surely important in management, as you're required to organize and lead people. But the problem with delegators is that  delegation is the only thing that they do, and this is not good. Managers are supposed to delegate, of course, but their work must add value. I've seen many managers that delegate all work in such a manner that they can be easily changed with a little bit more complex mail routing script. This will definitely not bring added value. If you see a delegator in your company, fire him and shorten the reporting line.
Related to my previous post, intentional managers are mostly delegators, and accidental managers do too little delegation.